Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Search results

  1. B

    Problems with Commodore 1084S-P VDE PSU

    Below C132 you drew a red ground icon. Although it makes sense for a ground connection to be there, C132 absolutely must be healthy not leaky. There's a chance it provides a snubber effect, in order to substitute for the DCR arrangement D133 C133 R133 which is often installed as a snubbing...
  2. B

    multiple bjt switch circuit interpretation

    Your initial schematic looks as though its supply is positive polarity. Shown below is conventional usage of PNP (in common emitter operation). My schematic flips the PNP icon so that its arrow points downward. The arrow indicates the direction of a PN junction, therefore direction of current...
  3. B

    How to make a SW amplifier work with a telescopic antenna radio?

    Metal plumbing often goes to earth ground. Example, faucets, radiators, baseboards. You only need wire and alligator clips. However it won't work if any plastic pipe intervenes (very likely compared to decades ago). To test continuity, hook up an AC voltmeter between live house voltage and your...
  4. B

    I want to learn Mechanical engineering from scratch..I am from Electronic & Instrumentation background

    Your terms (mechanical engineering, energy viewpoint, Mechatronics & Industrial Robotics hobbyist, Electronic & Instrumentation background)... bring to mind these topics: * motors (speed, torque, construction, available options, power usage) * batteries (construction, installation, power...
  5. B

    Resistance measurement/display without LCD, needle meter or 7-segment led?

    Make a comparator from a logic gate. The output turns on one or the other led, depending on whether your unknown resistor (DUT) is greater or lower than your resistance decade box (potentiometer). The change of state is automatically set where the input crosses 1/2 supply voltage. Therefore when...
  6. B

    How to make a SW amplifier work with a telescopic antenna radio?

    According to the article the circuit is comparable to 20-30 feet of wire antenna. (The drawing has its antenna labelled as 18 inches.) The traditional long wire hung in a tree greatly improved reception in my shortwave radio. (At the time I don't think I ran a ground wire.) An amplified...
  7. B

    +/-20V, few hundreds mA split rail?

    Example of twin voltage doublers creating split supply, +20-20V. The supply is 12VAC peak. (The 5 ohm resistor is unnecessary.) If your supply is DC then you can place this entire layout across a full H-bridge gated to apply 12VAC.
  8. B

    Help with prototype designing

    There is a hi-tech instrument that can detect an unseen break in a cable and its distance from the end. Another hi-tech store-bought instrument can 'see' through a plasterboard wall, just like radar, to tell the difference between wood, wires, and pipes. Your project might work by sending a...
  9. B

    Modern low noise bench top power supply

    Example of buck converter, adjustable output voltage. The invert-gate produces snap action On-Off. The NPN biases the PNP in order to allow a low voltage to control a high supply voltage. It's safer if the supply voltage comes from a step-down transformer.
  10. B

    Steady State Analysis

    Voltage multipliers (most of them) make use of one or more charge pump capacitors. The cap charges in one direction through a diode during one half of the cycle, then discharges through a different diode during the other half of the cycle. Your circuit has more than one stage. With light load...
  11. B

    TV antenna impedance plotting...

    Seems like directionality is a more prominent factor, which determines voltage and current produced by the antenna at a given frequency. Impedance relates directly to voltage and current, or rather, the ratio of voltage to current. If there's any current flowing, then it implies a load is...
  12. B

    Is bluetooth earbuds permanently damaged or it possible to repair?

    Did you determine which is at fault, the base or the earbuds? Soap and soapy water conduct electricity to some extent. It could short circuit something in your devices. It's up to you whether to take the risk of washing the insides with water. Maybe you can fix it, maybe you can't.
  13. B

    Microwave detection circuit verification

    A large assortment of simple rf detector circuits can be found via internet search. Many have a long antenna wire instead of the inductor used in your schematic.
  14. B

    Current sources within a differential cascoded structure

    Yes, it's expected that multiple current sources lead to 'fighting', if that's the focus of your question. As for the long-tail pair, it's true even with just one current source (that is, tail current in the basic configuration), the differential detection operates by means of the left column...
  15. B

    full bridge class D dead times, symmetrical?

    Operated as class D the H-bridge is like a buck converter first in one direction, then the other direction. Your gating scheme should duplicate this action. Rapid switching is done only to one transistor at a time. My simulation mimics an H-bridge by using two op amps (whose output stage is a...
  16. B

    Ceramic capacitor is blowing at random time

    Picture a little 1uF capacitor, its thin plates must endure 15 Amperes of current rushing across them in one direction, then the other, thousands of times per second. It may be necessary to split the burden across several capacitors in parallel. Say ten 100 nF.
  17. B

    Creating an "long life" LED flashlight for underwater triggercam

    Suppose you turn on the led once per minute, briefly? And if motion is detected then let it shine while you run the camera? Or if you're talking about a remote-control switch, then a radio transmitter and receiver is probably what you need. The receiver can be a pocket radio Or if you're close...
  18. B

    How to describe delta convolution using integral expression

    Looks similar to a double-slit experiment which produces interference patterns. Does that concept have equations which relate to your equations?
  19. B

    Single Output Positive & Negative DC-DC Converter

    From the sound of it you wish to send current in either direction through a single load. Is that correct? A full H-bridge is able to do the job. Dial the potentiometer to change amplitude and direction of current to load. Notice the leftmost half-bridge has NPN at top. The rightmost half-bridge...
  20. B


    Some appliances have a RESET in the form of a pinhole where you press a toothpick for 15 seconds. Some instructions say it makes a difference whether you unplug the power during reset, as to whether it resets all functions or some functions.

Part and Inventory Search